If the setup instructions above don't work for your particular OS setup, for whatever reason, you can get the ball rolling by installing these tools in whatever way you can and then getting them to work with the Makefile in circuitpython/ports/atmel-samd. (main branch):
- All Python packages listed in requirements-dev.txt. You will need to clone the repository to see that file.
- ARM gcc toolchain: https://developer.arm.com/open-source/gnu-toolchain/gnu-rm/downloads
See information about which gcc version to pick on the Linux Setup page of this guide.